WO2024011734A1

WO2024011734A1 - Fault early warning method for hydraulic system

Info

Publication number: WO2024011734A1
Application number: PCT/CN2022/117040
Authority: WO
Inventors: 刘永诚; 王建伟; 李明升; 李富红; 马忠章; 冯晓宇
Original assignee: 烟台杰瑞石油装备技术有限公司
Priority date: 2022-07-15
Filing date: 2022-09-05
Publication date: 2024-01-18
Also published as: CN115095579B; CN115095579A

Abstract

Disclosed is a fault early warning method for a hydraulic system, comprising: according to a preset data acquisition rule, acquiring target data information of at least two target parameters corresponding to a fault diagnosis index in a hydraulic system; according to the acquired target data information, determining a fault diagnosis result corresponding to the fault diagnosis index; and according to the fault diagnosis result, executing a fault early warning operation corresponding to the fault diagnosis index.

Description

Fault warning method for hydraulic system

field

The present disclosure relates to the technical field of hydraulic systems, and more specifically to a fault early warning method of a hydraulic system.

background

In order to realize intelligent fault warning of the hydraulic system, sensors for parameter collection are usually installed at the corresponding positions of the components to be monitored in the hydraulic system. During the working process of the hydraulic system, the sensors collect the data information of the corresponding parameters in real time. , and compare the collected data information with the preset threshold, and provide a fault warning when a fault occurs.

However, the above-mentioned fault warning method of the hydraulic system still uses a single parameter information for judgment, and does not consider the connection between the data information collected by each sensor, which may make the fault warning results inaccurate. Moreover, due to the large number of pending problems in the hydraulic system, The real-time operation status of diagnostic indicators cannot be directly obtained through sensors, so it is impossible to provide fault warning for the operation status of many indicators to be diagnosed in the hydraulic system, and thus it is impossible to achieve comprehensive fault warning for the hydraulic system.

Overview

In a first aspect, the present disclosure provides a fault early warning method for a hydraulic system, including:

According to the preset data collection rules, obtain the target data information of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system;

Determine the fault diagnosis result corresponding to the fault diagnosis indicator according to the obtained target data information;

According to the fault diagnosis result, a fault warning operation corresponding to the fault diagnosis indicator is performed.

In some embodiments, the fault diagnosis indicator is clogging of the oil suction filter;

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the pressure difference value of the oil suction filter and the first temperature value of the hydraulic oil tank;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

When the pressure difference value is greater than the first preset threshold and the first temperature value is greater than or equal to the second preset threshold, the oil suction filter is clogged. The second preset threshold represents the oil in the hydraulic oil tank. low temperature preset value.

In some embodiments, the fault diagnosis indicator is the oil suction condition of the hydraulic pump;

Obtain the negative pressure value of the oil suction pipeline and the second temperature value of the hydraulic oil tank;

When the negative pressure value is less than or equal to the third preset threshold, the oil suction resistance of the hydraulic pump is large and the oil suction valve in the hydraulic pump is not opened;

When the negative pressure value is greater than the third preset threshold, the negative pressure value is less than the fourth preset threshold, and the second temperature value is less than the second preset threshold, the oil suction resistance of the hydraulic pump is large. And the oil temperature in the hydraulic oil tank is low, the second preset threshold represents the low temperature preset value of the oil in the hydraulic oil tank, and the fourth preset threshold is greater than the third preset threshold;

When the negative pressure value is greater than the third preset threshold, the negative pressure value is less than the fourth preset threshold, and the second temperature value is greater than or equal to the second preset threshold, then the hydraulic pressure The pump has high suction resistance and the suction filter is clogged.

In some embodiments, the fault diagnosis indicator is the volumetric efficiency of a hydraulic pump, and the hydraulic pump is a variable hydraulic pump:

Obtain the first actual flow rate of the hydraulic pump, the first rotation speed of the hydraulic pump, and the first pressure value and the second pressure value at both ends of the servo cylinder in the hydraulic pump;

Determine the first theoretical flow rate of the hydraulic pump according to the first pressure value, the second pressure value and the first rotation speed;

determining a first volumetric efficiency of the hydraulic pump based on the first actual flow rate and the first theoretical flow rate;

When the first volumetric efficiency is less than the fifth preset threshold, the hydraulic pump fails.

In some embodiments, when the fault diagnosis index is the volumetric efficiency of the hydraulic pump and the hydraulic pump is a variable hydraulic pump, the target of obtaining at least two target parameters corresponding to the fault diagnosis index in the hydraulic system is Data information, including:

Obtain the second actual flow rate of the hydraulic pump, the second rotation speed of the hydraulic pump, and the third pressure value and the fourth pressure value at both ends of the reversing valve in the hydraulic pump;

Determine the second theoretical flow rate of the hydraulic pump according to the third pressure value, the fourth pressure value and the second rotation speed;

determining a second volumetric efficiency of the hydraulic pump based on the second actual flow rate and the second theoretical flow rate;

When the second volumetric efficiency is less than the fifth preset threshold, the hydraulic pump fails.

In some embodiments, the fault diagnosis indicator is the volumetric efficiency of a hydraulic motor, and the hydraulic motor is a variable displacement hydraulic motor:

Obtain the third actual flow rate of the hydraulic motor, the third rotation speed of the hydraulic motor, and the fifth and sixth pressure values at both ends of the servo piston in the hydraulic motor;

Determine a third theoretical flow rate of the hydraulic motor according to the fifth pressure value, the sixth pressure value and the third rotation speed;

determining a third volumetric efficiency of the hydraulic motor according to the third actual flow rate and the third theoretical flow rate;

When the third volumetric efficiency is less than the sixth preset threshold, the hydraulic motor fails.

In certain embodiments, the first theoretical flow rate and the second theoretical flow rate are determined as follows;

Determine the seventh pressure value corresponding to the dead zone of the first swash plate in the hydraulic pump, the first maximum displacement of the hydraulic pump, and the eighth pressure value corresponding to the first maximum displacement;

Determine the first theoretical displacement of the hydraulic pump according to the first pressure value, the second pressure value, the seventh pressure value, the first maximum displacement and the eighth pressure value;

Determine a second theoretical displacement of the hydraulic pump according to the third pressure value, the fourth pressure value, the seventh pressure value, the first maximum displacement and the eighth pressure value;

The first theoretical flow rate is determined based on the first theoretical displacement and the first rotation speed, and the second theoretical flow rate is determined based on the second theoretical displacement and the first rotation speed.

In certain embodiments, the third theoretical flow rate is determined as follows:

Determine the ninth pressure value corresponding to the dead zone of the second swash plate in the hydraulic motor, the second maximum displacement of the hydraulic motor, and the tenth pressure value corresponding to the second maximum displacement;

Determine a third theoretical displacement of the hydraulic pump according to the fifth pressure value, the sixth pressure value, the ninth pressure value, the second maximum displacement and the tenth pressure value;

The third theoretical flow rate is determined based on the third theoretical displacement and the third rotation speed.

In some embodiments, the fault diagnosis indicator is the oil replenishment status of the oil charge pump;

Obtain the oil charge pressure value of the oil charge pump, the first fault diagnosis result corresponding to the volumetric efficiency of the hydraulic pump, and the second fault diagnosis result corresponding to the volumetric efficiency of the hydraulic motor;

When the first fault diagnosis result is that the hydraulic pump is normal, the second fault diagnosis result is that the hydraulic motor is normal, and the oil charge pressure value is less than a seventh preset threshold, then the oil charge pump is faulty.

In certain embodiments, the method further includes:

After the hydraulic system is started, when the working time of the hydraulic system reaches the preset time threshold, the target data of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system are obtained according to the preset data collection rules. Information steps.

In some embodiments of the present disclosure, the fault early warning method of the hydraulic system includes: acquiring target data information of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system according to preset data collection rules; according to the acquired target data information to determine the fault diagnosis results corresponding to the fault diagnosis indicators; based on the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators. In some embodiments, through the above fault warning method, the present disclosure takes into account the connection between the data information collected by different sensors during the fault warning process of the hydraulic system, and aims at a fault diagnosis index by obtaining the fault diagnosis index. data information about multiple parameters, and process the multiple data information obtained to make the fault diagnosis results of the fault diagnosis indicators more accurate, and to perform fault diagnosis indicators that cannot be directly obtained through sensors. Fault warning improves the comprehensiveness of hydraulic system fault warning.

Brief description of the drawings

Figure 1 is a schematic diagram of a hydraulic system according to an embodiment of the present disclosure;

Figure 2 is a schematic flowchart of a fault early warning method for a hydraulic system according to an embodiment of the present disclosure;

Figure 3 is a schematic flow chart of a fault diagnosis method for clogging of an oil suction filter according to an embodiment of the present disclosure;

Figure 4 is a schematic flowchart of a method for fault diagnosis of oil suction conditions of a hydraulic pump according to an embodiment of the present disclosure;

Figure 5 is a schematic flowchart of a fault diagnosis method for the volumetric efficiency of a hydraulic pump according to an embodiment of the present disclosure;

Figure 6 is a schematic flowchart of a fault diagnosis method for the volumetric efficiency of a hydraulic pump according to an embodiment of the present disclosure;

Figure 7 is a schematic flowchart of a fault diagnosis method for volumetric efficiency of a hydraulic motor according to an embodiment of the present disclosure;

Figure 8 is a schematic flowchart of a fault diagnosis method for the oil replenishment situation of the oil charge pump according to an embodiment of the present disclosure;

In the above attached picture:

10. Hydraulic oil tank; 20. Oil suction filter; 30. Hydraulic pump; 31. Hydraulic pump body; 32. Servo cylinder; 33. Directional valve; 40. First pipeline filter; 50. Second pipeline filter ; 60. Hydraulic motor; 61. Hydraulic motor body; 70. Radiator; 80. Return oil filter; 90. Oil charge pump;

101. The first differential pressure transmitter; 102. The second differential pressure transmitter; 103. The third differential pressure transmitter; 104. The fourth differential pressure transmitter;

201. Particle size detector;

301. First pressure sensor; 302. Second pressure sensor; 303. Third pressure sensor; 304. Fourth pressure sensor; 305. Fifth pressure sensor; 306. Sixth pressure sensor; 307. Ninth pressure sensor;

401. First flow sensor; 402. Second flow sensor; 403. Third flow sensor; 404. Fourth flow sensor;

501. First temperature sensor; 502. Second temperature sensor; 503. Third temperature sensor; 504. Fourth pressure sensor; 505. Fifth pressure sensor;

601. First speed sensor; 602. Second speed sensor;

701. Negative pressure sensor;

801. Liquid level sensor.

Elaborate

In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments These are some embodiments of the present disclosure, but not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this disclosure.

In order to facilitate understanding of the embodiments of the present disclosure, specific embodiments will be further explained below with reference to the accompanying drawings. The embodiments do not constitute limitations to the embodiments of the present disclosure.

Referring to Figure 1, Figure 1 is a schematic diagram of a hydraulic system provided by an embodiment of the present disclosure. The hydraulic system provided by an embodiment of the present disclosure is a closed hydraulic system. The closed hydraulic system includes a hydraulic oil tank 10, an oil suction filter 20, a hydraulic pump 30, a first pipeline filter 40, a second pipeline filter 50, Motor 60, radiator 70, return oil filter 80 and charge pump 90. The hydraulic pump 30 includes a hydraulic pump body 31, a servo cylinder 32, a reversing valve 33 and a first swash plate (not shown in the figure), and the hydraulic motor 60 includes a hydraulic motor body 61 and a servo piston (not shown in the figure). out) and the second swash plate (not shown in the figure). The power source of the hydraulic system can be directly driven by a prime mover such as an engine or a motor, or can be driven by a prime mover including but not limited to a transfer case, a transmission shaft, a power take-off, a reducer, etc. to drive the hydraulic pump 30. The hydraulic pump 30 is The oil suction filter 20 sucks oil from the hydraulic oil tank 10, and the output high-pressure oil drives the hydraulic motor 60 to rotate through the main pipeline of the hydraulic pump 30. The first pipeline filter 40 and the second filter provided on the main pipeline filter out the main oil. Impurities in the road. The drained oil from the housing of the hydraulic pump 30 and the hydraulic motor 60 passes through the radiator 70 for heat dissipation. The heat-dissipated oil is filtered by the oil return filter 80 and then returned to the hydraulic oil tank 10 .

In order to realize fault warning of the hydraulic system, the hydraulic system is equipped with multiple sensors for data information collection, such as pressure sensor, flow sensor, temperature sensor, speed sensor, liquid level sensor, particle size detector and pressure difference generator. sensors, etc. The installation location and functions of each sensor will be explained one by one below.

The oil suction filter 20 in the hydraulic system is provided with a first pressure difference transmitter 101, the first pipeline filter 40 is provided with a second pressure difference transmitter 102, and the second pipeline filter 50 is provided with a third pressure difference transmitter 102. Three differential pressure transmitters 103 and a fourth differential pressure transmitter 104 are provided on the oil return filter 80. By setting each differential pressure transmitter, the differential pressure value of the corresponding filter is collected.

A particle size detector 201 is provided in the hydraulic system. The particle size detector 201 can be installed at one or more locations in the oil suction pipeline, the oil return pipeline, the oil drain pipeline and the oil tank. The particle size detector 201 is used to collect oil. The number of impurities and water content in the oil. When the number of impurities and water content in the oil exceed the set mark, the oil quality is poor and the oil needs to be replaced. The fault diagnosis results are used to provide a fault warning.

A negative pressure sensor 701 is provided in the oil suction pipeline in the hydraulic system, and the negative pressure sensor 701 is used to collect the negative pressure value in the oil suction pipeline.

The main oil pipeline in the hydraulic system is provided with a first pressure sensor 301 and a second pressure sensor 302, and a third pressure sensor 303 and a fourth pressure sensor 304 are provided at both ends of the servo cylinder 32 in the hydraulic pump 30. The hydraulic pump 30 China A fifth pressure sensor 305 and a sixth pressure sensor 306 are provided at both ends of the reversing valve 33, and a seventh pressure sensor (not shown in the figure) and an eighth pressure sensor (not shown in the figure) are provided at both ends of the servo piston in the hydraulic motor 60. (not shown in the figure), the charge pump 90 is provided with a ninth pressure sensor 307 . Each pressure sensor is used to collect the pressure value at the corresponding position, the servo cylinder 32 is used to control the displacement change of the hydraulic pump 30 , the reversing valve 33 is used to control the action of the servo cylinder 32 , and the servo piston is used to control the movement of the hydraulic motor 60 Displacement changes.

The main oil pipeline in the hydraulic system is provided with a first flow sensor 401 and a second flow sensor 402. The first flow sensor 401 and the second flow sensor 402 are used to collect the oil flow in the main oil pipeline. The hydraulic system is also equipped with The third flow sensor 403 and the fourth flow sensor 404 , the third flow sensor 403 is used to collect the case leakage flow of the hydraulic pump 30 , and the fourth flow sensor 404 is used to collect the case leakage flow of the hydraulic motor 60 . Flow sensors can include, but are not limited to, turbine flowmeters and ultrasonic flowmeters.

The hydraulic oil tank 10 in the hydraulic system is provided with a liquid level sensor 801. The liquid level sensor 801 is used to collect the liquid level of the oil in the hydraulic oil tank 10. The liquid level sensor 801 may be in the form of a level meter or a guided wave radar. form. When the collected liquid level is lower than the low liquid level setting value, there may be insufficient oil in the hydraulic oil tank 10 or oil leakage from the pipeline. When the collected liquid level is higher than the high liquid level setting value, then there may be insufficient oil in the hydraulic oil tank 10 Water may have entered.

The hydraulic pump 30 in the hydraulic system is provided with a first temperature sensor 501, the hydraulic motor 60 is provided with a second temperature sensor 502, a third temperature sensor 503 is provided at the inlet of the radiator 70, and at the outlet of the radiator 70 A fourth temperature sensor 504 is provided, and a fifth temperature sensor 505 is provided in the hydraulic oil tank 10. Each temperature sensor is used to collect the temperature value at the corresponding position. When the temperature value exceeds the temperature warning value, a fault warning is issued, and when the temperature value If the temperature limit is exceeded, shutdown is recommended. Temperature sensor types can be selected including but not limited to probe rod type, patch type, etc.

The hydraulic system is provided with a first rotational speed sensor 601 and a second rotational speed sensor 602. The first rotational speed sensor 601 is used to collect the rotational speed of the hydraulic pump 30. If it cannot be directly detected, it can be based on the rotational speed of the prime mover and the driving parameters of the prime mover. Limited to the speed ratio of the transfer case, transmission shaft, power take-off, reducer, etc., the speed of the hydraulic pump 30 is calculated indirectly (for example, the speed of the hydraulic pump 30 = engine speed × transfer case speed ratio). The second rotation speed sensor 602 is used to collect the rotation speed of the hydraulic motor 60 . If it cannot be directly detected, the speed of the hydraulic motor 60 can be calculated indirectly based on the mechanical structure of the motor drive and the speed ratio of the transfer case, transmission shaft, reducer, etc. (for example, the speed of the hydraulic motor 60 = the speed of the mechanical structure/transfer box speed ratio). The types of speed sensors that can be selected include, but are not limited to, tooth plate type, spindle encoder type, infrared induction type, etc.

In this embodiment, all sensors collect information and record and store it through data collection modules (including but not limited to current collection modules, counting modules, PLC, etc.). In order to save storage space and facilitate subsequent fault analysis, the data collection frequency can be based on actual conditions. Situation adjustment (such as 5 times/second, 1 time/second, etc.), if necessary, can be changed to a higher acquisition frequency in the event of a failure. The fault information needs to be displayed on the display screen at the operating position, and the cause of the fault must be clarified, and solutions or suggestions must be given for the fault, including but not limited to drawings, parts manuals, samples, operating instructions, etc. In order to avoid a sudden failure, relevant alarm information must have a failure warning, so that equipment users can intervene in maintenance in advance and avoid equipment damage or economic losses. At the same time, fault information will be transmitted back to the equipment manufacturer through appropriate communication channels, making it easier for the manufacturer to provide after-sales service and formulate sales strategies.

It can be seen that by setting sensors at corresponding positions in the hydraulic system, the sensors are used to collect data information of corresponding parameters, and by comparing the data information with the settings, fault diagnosis is performed, and when a fault occurs, a fault warning is provided. However, using a single data information for fault diagnosis may make the fault warning results inaccurate, and it is impossible to achieve comprehensive fault warning for the hydraulic system. In order to solve this problem, it will be elaborated in the following embodiments, as follows.

Referring to FIG. 2 , FIG. 2 is a schematic flowchart of a fault early warning method for a hydraulic system provided by an embodiment of the present disclosure. The fault early warning method provided by the embodiment of the present disclosure includes the following steps:

S101: According to the preset data collection rules, obtain the target data information of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system.

Among them, the data collection rules can be preset according to the fault diagnosis indicators required for fault diagnosis. The data collection rules are the data information of the parameters that need to be collected when the fault diagnosis indicators need to be diagnosed. In order to improve the accuracy and comprehensiveness of fault diagnosis of the hydraulic system, when performing fault diagnosis for each fault diagnosis indicator, it is necessary to obtain target data information of at least two target parameters. For example, in view of the high oil temperature of the hydraulic pump and the oil temperature of the hydraulic motor, the traditional fault warning method combines the temperature value collected by the first temperature sensor with the set value and the temperature value collected by the second temperature sensor with the set value. Just compare the fixed value, but because the high oil temperature in the hydraulic oil tank will also cause the high oil temperature of the hydraulic pump and the high oil temperature of the hydraulic motor, so the fault diagnosis indicator of the high oil temperature of the hydraulic pump is , it is necessary to combine the temperature value collected by the first temperature sensor and the temperature value collected by the fifth temperature sensor in the hydraulic oil tank for fault diagnosis. When the temperature value collected by the fifth sensor is greater than the set value (the set value is the hydraulic oil tank When the temperature value collected by the first temperature sensor is greater than the set value, the temperature of the oil in the hydraulic oil tank is high. When the temperature value collected by the fifth sensor is less than or equal to the set value And when the temperature value collected by the first temperature sensor is greater than the set value, the hydraulic pump fails. For the fault diagnosis index of high temperature of oil in the hydraulic motor, it is necessary to combine the temperature value collected by the second temperature sensor and the temperature value collected by the fifth temperature sensor in the hydraulic oil tank for fault diagnosis. When the temperature value collected by the fifth sensor When the value is greater than the set value (the set value is the high temperature set value of the oil in the hydraulic oil tank) and the temperature value collected by the first temperature sensor is greater than the set value, the temperature of the oil in the hydraulic oil tank is high. When the temperature value collected by the fifth sensor is less than or equal to the set value and the temperature value collected by the second temperature sensor is greater than the set value, the hydraulic motor fails. By integrating the data collected by different sensors, fault warning can be carried out to improve the accuracy of fault warning.

In this embodiment, before executing step S101, the fault warning method provided by this embodiment also includes:

After the hydraulic system is started, when the working time of the hydraulic system reaches the preset time threshold, step S101 is executed.

In order to avoid fault warning of the hydraulic system, a preset time threshold is set to ensure that the hydraulic system enters normal operation after startup before performing fault diagnosis and fault warning. In this embodiment, the preset duration threshold can be set according to actual needs, and is not specifically limited in this embodiment. For example, the preset duration threshold may be 5 seconds.

S102: Determine the fault diagnosis results corresponding to the fault diagnosis indicators based on the obtained target data information.

Among them, after obtaining the target data information of at least two target parameters corresponding to the fault diagnosis index, fault diagnosis is performed on the obtained target data information according to the preset diagnosis conditions corresponding to the fault diagnosis index, so that the fault diagnosis can be obtained The fault diagnosis results corresponding to the indicators include normal and fault. In this embodiment, the preset diagnostic conditions are preset according to the relationship between different parameters. The corresponding relationship between the fault diagnosis indicators and the preset diagnostic conditions will be described below, and will not be described again in this embodiment.

S103: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

Among them, when the fault diagnosis result is normal, it can be displayed on the display screen to remind the user that the component corresponding to the fault diagnosis indicator is normal; when the fault diagnosis result is abnormal, it can also be displayed on the display screen to remind the relevant personnel of the fault. Of course, the component failure corresponding to the diagnostic index can also be pre-warned through sound and light. In this embodiment, the failure pre-warning method is not specifically limited and can be selected according to actual needs.

It can be seen that the fault early warning method of the hydraulic system provided by this embodiment, during the fault early warning process of the hydraulic system, takes into account the connection between the data information collected by different sensors, and targets a fault diagnosis index by obtaining the fault diagnosis index. data information about multiple parameters, and process the multiple data information obtained to make the fault diagnosis results of the fault diagnosis indicators more accurate, and to perform fault diagnosis indicators that cannot be directly obtained through sensors. Fault warning improves the comprehensiveness of hydraulic system fault warning.

Referring to FIG. 3 , FIG. 3 is a schematic flow chart of a fault diagnosis method for clogging of an oil suction filter provided in this embodiment. The fault diagnosis method provided in this embodiment includes the following steps:

S201: According to the preset data collection rules, obtain the pressure difference value of the oil suction filter and the first temperature value of the hydraulic oil tank corresponding to the fault diagnosis index in the hydraulic system. The fault diagnosis index is the clogging of the oil suction filter.

In this embodiment, the pressure difference value of the oil suction filter is collected by the first pressure difference transmitter provided on the oil suction filter, and the first temperature value of the hydraulic oil tank is collected by the fifth temperature sensor provided in the hydraulic oil tank. . Due to the low temperature of the oil or the high viscosity of the oil, the pressure difference value may exceed the set value. For the fault warning of the clogging of the oil suction filter, if only the pressure difference value collected by the first pressure difference transmitter is used for oil suction Fault diagnosis of filter clogging can easily lead to inaccurate fault diagnosis results, so fault diagnosis must be based on the temperature value of the oil collected by the fifth temperature sensor installed in the hydraulic oil tank. Therefore, for the fault diagnosis indicator of clogging of the oil suction filter, the data collection rule is to obtain the pressure difference value collected by the first pressure difference transmitter and the first temperature value collected by the fifth temperature sensor.

S202: Determine whether the preset diagnosis conditions corresponding to the fault diagnosis indicators are met. The preset diagnosis conditions are that the pressure difference value is greater than the first preset threshold and the first temperature value is greater than or equal to the second preset threshold.

In this embodiment, the first preset threshold represents the limit value of the pressure difference of the oil suction filter, and the second preset threshold represents the low temperature preset value of the oil in the hydraulic oil tank. The preset diagnostic condition is the condition that the oil suction filter is clogged. When the preset diagnostic condition is met, the oil suction filter is clogged. When the preset diagnostic condition is not met, the oil suction filter is not clogged. In this embodiment, both the first preset threshold and the second preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the first preset threshold may be 0.15 bar, and the second preset threshold may be 10°C.

S203: When the preset diagnosis conditions corresponding to the fault diagnosis index are met, the fault diagnosis result corresponding to the fault diagnosis index is that the oil suction filter is clogged.

In this embodiment, when the first temperature value is less than the second preset threshold, it means that the oil temperature in the hydraulic oil tank is too low. If the oil temperature is too low, the pressure difference value collected by the first pressure difference transmitter may be affected. is greater than the first preset threshold, but the oil suction filter may not be clogged at this time. Therefore, only when the pressure difference value is greater than the first preset threshold and the oil temperature in the hydraulic oil tank is not too low (that is, the first temperature value is greater than or equal to the second preset threshold), the oil suction filter is diagnosed as clogged.

S204: When the preset diagnosis conditions corresponding to the fault diagnosis index are not met, the fault diagnosis result corresponding to the fault diagnosis index is that the oil suction filter is not clogged.

In this embodiment, failure to meet the preset diagnostic condition may specifically refer to the pressure difference value being less than or equal to the first preset threshold, or the pressure difference value being greater than the first preset threshold and the first temperature value being less than the second preset threshold.

S205: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

In this embodiment, when the fault diagnosis result is that the oil suction filter is clogged, a fault warning can be provided through the display screen or other methods mentioned above; when the fault diagnosis result is that the oil suction filter is not clogged, a fault warning can also be provided through the display screen or other methods mentioned above. remind.

It can be seen that when performing fault diagnosis on the fault diagnosis indicator of the clogging of the oil suction filter, the data information collected by the first pressure difference transmitter in the oil suction filter and the first temperature sensor in the hydraulic oil tank are combined to diagnose the fault. Diagnosis improves the accuracy of fault diagnosis and avoids the problem of low accuracy in fault diagnosis only through the data information collected by the first differential pressure transmitter.

Referring to FIG. 4 , FIG. 4 is a schematic flowchart of a method for fault diagnosis of oil suction conditions of a hydraulic pump according to an embodiment of the present disclosure. The fault diagnosis method provided in this embodiment includes the following steps:

S301: According to the preset data collection rules, obtain the negative pressure value of the oil suction pipeline and the second temperature value of the hydraulic oil tank corresponding to the fault diagnosis index in the hydraulic system. The fault diagnosis index is the oil suction condition of the hydraulic pump.

In this embodiment, the negative pressure value of the oil suction pipeline is collected by a negative pressure sensor provided on the oil suction pipeline, and the second temperature value of the hydraulic oil tank is collected by a fifth temperature sensor provided in the hydraulic oil tank. When using the traditional method to diagnose the oil suction fault of the hydraulic pump, the negative pressure value is compared with the set value. However, the traditional method cannot clarify the specific reasons for the high oil suction resistance of the hydraulic pump. When it is determined that the hydraulic pump has high oil suction resistance, it is necessary to troubleshoot the hydraulic system, which affects work efficiency and the accuracy of fault diagnosis. Since the oil is viscous at low temperature, the oil suction valve is not opened, and the oil suction filter is clogged, the hydraulic pump may have a large oil suction resistance. If only the negative pressure value collected by the negative pressure sensor is used to diagnose the oil suction condition of the hydraulic pump, it cannot be accurately diagnosed. The specific reason for the large oil suction resistance of the hydraulic pump requires comprehensive fault diagnosis based on the second temperature value of the oil collected by the fifth temperature sensor installed in the hydraulic tank. Therefore, for the fault diagnosis indicator of the oil suction condition of the hydraulic pump, the data collection rule is to obtain the negative pressure value collected by the negative pressure sensor and the second temperature value collected by the fifth temperature sensor.

S302: Determine whether the first preset diagnosis condition corresponding to the fault diagnosis index is met. The first preset diagnosis condition is that the negative pressure value is less than or equal to the third preset threshold.

In this embodiment, the third preset threshold represents the limit value of the negative pressure value of the hydraulic pump. The first preset diagnosis condition is the condition of large oil suction resistance of the hydraulic pump. When the first preset diagnosis condition is met, the oil suction resistance of the hydraulic pump is large. When the first preset diagnosis condition is not met, the second preset diagnosis needs to be performed. Judgment of conditions. In this embodiment, the third preset threshold can be set according to actual needs, and is not specifically limited in this embodiment. For example, the third preset threshold can be -0.5 bar.

S303: When the first preset diagnosis condition is met, the fault diagnosis result corresponding to the fault diagnosis index is that the oil suction resistance of the hydraulic pump is large and the oil suction valve in the hydraulic pump is not opened.

In this embodiment, when the first preset diagnostic condition is met, regardless of the temperature value of the oil in the hydraulic oil tank and the clogging of the oil suction filter, it can be determined that the reason for the high oil suction resistance of the hydraulic pump is that the oil suction valve is open.

S304: When the first preset diagnosis condition is not met, determine whether the second preset diagnosis condition corresponding to the fault diagnosis indicator is met. The second preset diagnosis condition is that the negative pressure value is greater than the third preset threshold and the negative pressure value is less than the third preset threshold. There are four preset thresholds, the second temperature value is less than the second preset threshold, and the fourth preset threshold is greater than the third preset threshold.

In this embodiment, the second preset threshold represents the low temperature preset value of the oil in the hydraulic tank. The second preset diagnostic condition is also the condition of large oil suction resistance of the hydraulic pump. When the second preset diagnostic condition is met, the hydraulic pump suction resistance is large. When the second preset diagnostic condition is not met, a third preset is required. Judgment of diagnostic conditions. The second preset diagnostic condition is to determine whether the specific cause of the high oil suction resistance of the hydraulic pump is the low oil temperature in the hydraulic oil tank. In this embodiment, the second preset threshold and the fourth preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the second preset threshold may be 10°C, and the fourth preset threshold may be -0.3 bar.

S305: When the first preset diagnosis condition is not met but the second preset diagnosis condition is met, the fault diagnosis result corresponding to the fault diagnosis index is that the oil suction resistance of the hydraulic pump is large and the oil temperature in the hydraulic oil tank is low.

In this embodiment, when the second preset diagnostic condition is met, it can be determined that the reason for the large oil suction resistance of the hydraulic pump is the low temperature in the hydraulic oil tank.

S306: When the second preset diagnosis condition is not met, determine whether the third preset diagnosis condition corresponding to the fault diagnosis indicator is met. The third preset diagnosis condition is that the negative pressure value is greater than the third preset threshold and the negative pressure value is less than the third preset threshold. Four preset thresholds and the second temperature value is greater than or equal to the second preset threshold.

In this embodiment, the third preset diagnostic condition is to determine whether the specific cause of the high oil suction resistance of the hydraulic pump is clogging of the oil suction filter. In this embodiment, reference may be made to the above description for the second preset threshold, the third preset threshold and the fourth preset threshold, which will not be described again in this embodiment.

S307: When the second preset diagnosis condition is not met, but the third preset diagnosis condition is met, the fault diagnosis result corresponding to the fault diagnosis indicator is that the oil suction resistance of the hydraulic pump is large and the oil suction filter is clogged.

In this embodiment, when the third preset diagnostic condition is met, it can be determined that the reason for the high oil suction resistance of the hydraulic pump is that the oil suction filter is clogged.

S308: When the third preset diagnosis condition is not met, the fault diagnosis result corresponding to the fault diagnosis index is that the oil suction resistance of the hydraulic pump is normal.

In this embodiment, neither the first preset diagnostic condition, nor the second preset diagnostic condition, nor the third preset diagnostic condition is satisfied may specifically mean that the negative pressure value is greater than or equal to the fourth preset threshold.

S309: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

In this embodiment, according to the first preset diagnostic condition, the second preset diagnostic condition and the third preset diagnostic condition, the oil suction situation of the hydraulic pump can be judged, and the specific cause of the large oil suction resistance of the hydraulic pump can be determined. When After obtaining the fault diagnosis results, the fault diagnosis results can be displayed on the display screen to achieve fault warning.

It can be seen that when performing fault diagnosis on the fault diagnosis indicator of the oil suction condition of the hydraulic pump, by integrating the data information collected by the negative pressure sensor in the hydraulic pump and the fifth temperature sensor in the hydraulic oil tank for fault diagnosis, not only can the fault diagnosis be improved The accuracy of the diagnosis can also clarify the specific reasons for the high oil suction resistance of the hydraulic pump, allowing relevant personnel to quickly eliminate the cause of the fault and improve work efficiency.

Referring to FIG. 5 , FIG. 5 is a schematic flowchart of a fault diagnosis method for the volumetric efficiency of a hydraulic pump provided in an embodiment. The fault diagnosis method provided in this embodiment includes the following steps:

S401: According to the preset data collection rules, obtain the first actual flow rate of the hydraulic pump corresponding to the fault diagnosis indicator in the hydraulic system, the first rotation speed of the hydraulic pump, and the first pressure value and the second pressure value at both ends of the servo cylinder in the hydraulic pump. , the fault diagnosis index is the volumetric efficiency of the hydraulic pump.

In this embodiment, the hydraulic pump is a variable hydraulic pump. It should be noted that when the hydraulic pump has its own displacement indication sensor, the first volumetric efficiency of the hydraulic pump can be determined directly through the calculation formula of the volumetric efficiency of the hydraulic pump. The data information collected by the displacement indication sensor is the theoretical displacement of the hydraulic pump. The calculation formula of volumetric efficiency is: (actual flow rate of the hydraulic pump/theoretical flow rate of the hydraulic pump)*100%, where the theoretical flow rate of the hydraulic pump = hydraulic pressure The theoretical displacement of the pump × the speed of the hydraulic pump, the actual flow of the hydraulic pump can be obtained through the flow sensor on the output main oil pipeline. Among them, the output main oil pipeline can be determined according to the rotation direction of the hydraulic motor in the hydraulic system, and the data information collected by the flow sensor (the first flow sensor or the second flow sensor) in the main oil pipeline is output as the actual flow rate of the hydraulic pump. . The fault diagnosis method provided in this embodiment is aimed at how to fault diagnose the volumetric efficiency of the hydraulic pump when the hydraulic pump does not have a displacement indication sensor.

Among them, the first actual flow rate of the hydraulic pump is collected by the first flow sensor or the second flow sensor (for details, please refer to the above description), and the first pressure value and the second pressure value at both ends of the servo cylinder in the hydraulic pump are collected by the third pressure value. The first rotation speed of the hydraulic pump can be collected by the first rotation speed sensor and the fourth pressure sensor. Of course, the first rotation speed of the hydraulic pump can also be obtained indirectly by referring to the above.

S402: Determine the first theoretical flow rate of the hydraulic pump based on the first pressure value, the second pressure value and the first rotation speed.

In this embodiment, the first theoretical flow rate of the hydraulic pump can be determined in the following manner:

The first theoretical flow rate is determined based on the first theoretical displacement and the first rotation speed.

Among them, the first theoretical displacement = (P ₁ -P ₂ -P ₀₁ )×V ₁ /(P ₀₂ -P ₀₁ )

In the above formula, P ₁ represents the first pressure value, P ₂ represents the second pressure value, P ₀₁ represents the seventh pressure value, V ₁ represents the first maximum displacement, P ₀₂ represents the eighth pressure value, P ₁ >P ₂ , the positive and negative of the first pressure value and the second pressure value can indicate the direction of the hydraulic pump output flow, so when P ₁ <P ₂ , the first theoretical displacement = (P ₂ -P ₁ -P ₀₁ )×V ₁ /(P ₀₂ -P ₀₁ ).

In the above, the difference between the first pressure value and the second pressure value can represent the output flow of the hydraulic pump. The change in the pressure value is proportional to the change in the displacement. Therefore, the first pressure value and the second pressure can be used to calculate the output flow of the hydraulic pump. The pressure difference is used as a measure of displacement. Furthermore, there will be a dead zone (0<P<P ₀₁ ) during the startup process of the first swash plate in the hydraulic pump, that is, the displacement will not be output as soon as there is a difference between the first pressure value and the second pressure value. Therefore, it is necessary to find out and remove the impact of the dead zone on the displacement calculation during debugging; similarly, when the hydraulic pump displacement is limited and the pressure difference exceeds the upper limit of the displacement, the displacement does not change with the first pressure value and the second pressure value. As the pressure difference between the values increases and continues to increase, the displacement is the set first maximum displacement (V ₁ ) of the hydraulic pump. Among them, the seventh pressure value corresponding to the first swash plate dead zone in the hydraulic pump and the first maximum displacement of the hydraulic pump are both determined through pre-debugging and can be directly called and used when performing fault diagnosis.

S403: Determine the first volumetric efficiency of the hydraulic pump based on the first actual flow rate and the first theoretical flow rate.

The first volumetric efficiency of the hydraulic pump can be determined by using the first actual flow rate and the first theoretical flow rate according to the above-mentioned calculation formula of the hydraulic pump volumetric efficiency.

S404: Determine whether the preset diagnosis condition corresponding to the fault diagnosis index is met. The preset diagnosis condition is that the first volumetric efficiency is less than the fifth preset threshold.

In this embodiment, a fault warning threshold can also be set, and the fault warning threshold is greater than the fifth preset threshold. When the first volumetric efficiency of the hydraulic pump is less than the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is the hydraulic pump The volumetric efficiency is low. When the first volumetric efficiency of the hydraulic pump is greater than or equal to the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis indicator is that the volumetric efficiency of the hydraulic pump is normal. Among them, the fault warning threshold and the fifth preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the fault warning threshold may be 80%, and the fifth preset threshold may be 70%.

S405: When the preset diagnosis conditions corresponding to the fault diagnosis index are met, the fault diagnosis result corresponding to the fault diagnosis index is a hydraulic pump failure.

S406: When the preset diagnosis conditions corresponding to the fault diagnosis index are not met, the fault diagnosis result corresponding to the fault diagnosis index is that the hydraulic pump is normal.

S407: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

In this embodiment, when the fault diagnosis result is that the hydraulic pump is faulty, a fault warning can be provided through the display screen or other methods mentioned above; when the fault diagnosis result is that the hydraulic pump is normal, a reminder can also be provided through the display screen or other methods mentioned above.

It can be seen that when performing fault diagnosis on the fault diagnosis index of the volumetric efficiency of the hydraulic pump, when the hydraulic pump does not have its own displacement indication sensor, the volumetric efficiency of the hydraulic pump will be difficult to diagnose. By based on the pressure at both ends of the servo cylinder The value can realize real-time fault diagnosis of the volumetric efficiency of the hydraulic pump and improve the comprehensiveness of the hydraulic system fault early warning.

Referring to FIG. 6 , FIG. 6 is a schematic flowchart of a fault diagnosis method for the volumetric efficiency of a hydraulic pump provided in an embodiment. The fault diagnosis method provided in this embodiment includes the following steps:

S501: According to the preset data collection rules, obtain the second actual flow rate of the hydraulic pump corresponding to the fault diagnosis indicator in the hydraulic system, the second rotation speed of the hydraulic pump, and the third pressure value and fourth pressure value at both ends of the pressure change valve in the hydraulic pump. value, the fault diagnosis index is the volumetric efficiency of the hydraulic pump.

In this embodiment, the hydraulic pump is a variable displacement hydraulic pump. The fault diagnosis method provided in this embodiment is aimed at how to perform fault diagnosis on the volumetric efficiency of the hydraulic pump when the hydraulic pump does not have a displacement indication sensor.

Among them, the second actual flow rate of the hydraulic pump is collected by the first flow sensor or the second flow sensor (for details, please refer to the above-mentioned acquisition method of the first actual flow rate of the hydraulic pump, which will not be described in detail in this embodiment). The third pressure value and the fourth pressure value at both ends of the middle pressure exchange valve are collected by the fifth pressure sensor and the sixth pressure sensor. The second rotation speed of the hydraulic pump can be obtained by the first rotation speed sensor. Of course, you can also refer to the above The indirect acquisition of the second rotation speed of the hydraulic pump.

S502: Determine the second theoretical flow rate of the hydraulic pump based on the third pressure value, the fourth pressure value and the second rotation speed.

Determine the second theoretical displacement of the hydraulic pump according to the third pressure value, the fourth pressure value, the seventh pressure value, the first maximum displacement and the eighth pressure value;

The second theoretical flow rate is determined based on the second theoretical displacement and the first rotation speed.

Among them, the second theoretical displacement = (P ₃ -P ₄ -P ₀₁ )×V ₁ /(P ₀₂ -P ₀₁ )

In the above formula, P ₃ represents the third pressure value, P ₄ represents the fourth pressure value, P ₀₁ represents the seventh pressure value, V ₁ represents the first maximum displacement, P ₀₂ represents the eighth pressure value, P ₃ >P ₄ , the positive and negative of the third pressure value and the fourth pressure value can indicate the direction of the hydraulic pump output flow, so when P ₃ <P ₄ , the second theoretical displacement = (P ₄ -P ₃ -P ₀₁ )×V ₁ /(P ₀₂ -P ₀₁ ).

In the above, the difference between the third pressure value and the fourth pressure value can represent the output flow of the hydraulic pump. The change of the pressure value is proportional to the change of the displacement. Therefore, the third pressure value and the fourth pressure can be used to calculate the output flow of the hydraulic pump. The pressure difference is used as a measure of displacement. Furthermore, there will be a dead zone (0<P<P ₀₁ ) during the startup process of the first swash plate in the hydraulic pump, that is, the displacement will not be output as soon as there is a difference between the third pressure value and the fourth pressure value. Therefore, it is necessary to find out and remove the influence of the dead zone on the displacement calculation during debugging; similarly, when the hydraulic pump displacement is limited, when the pressure difference exceeds the upper limit of the displacement, the displacement does not change with the third pressure value and the fourth pressure value. As the pressure difference between the pressure values increases and continues to increase, the displacement is the set first maximum displacement (V ₁ ) of the hydraulic pump. Among them, the seventh pressure value corresponding to the first swash plate dead zone in the hydraulic pump and the first maximum displacement of the hydraulic pump are both determined through pre-debugging and can be directly called and used when performing fault diagnosis.

S503: Determine the second volumetric efficiency of the hydraulic pump based on the second actual flow rate and the second theoretical flow rate.

Wherein, the second volumetric efficiency of the hydraulic pump can be determined through the second actual flow rate and the second theoretical flow rate according to the above-mentioned calculation formula of the hydraulic pump volumetric efficiency.

S504: Determine whether the preset diagnosis condition corresponding to the fault diagnosis index is met. The preset diagnosis condition is that the second volumetric efficiency is less than the fifth preset threshold.

In this embodiment, similarly, a fault warning threshold can also be set. The fault warning threshold is greater than the fifth preset threshold. When the second volumetric efficiency of the hydraulic pump is less than the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis indicator is Because the volumetric efficiency of the hydraulic pump is low, when the second volumetric efficiency of the hydraulic pump is greater than or equal to the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is that the volumetric efficiency of the hydraulic pump is normal. Among them, the fault warning threshold and the fifth preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the fault warning threshold may be 80%, and the fifth preset threshold may be 70%.

S505: When the preset diagnosis conditions corresponding to the fault diagnosis index are met, the fault diagnosis result corresponding to the fault diagnosis index is a hydraulic pump failure.

S506: When the preset diagnosis conditions corresponding to the fault diagnosis index are not met, the fault diagnosis result corresponding to the fault diagnosis index is that the hydraulic pump is normal.

S507: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

It can be seen that when performing fault diagnosis on the fault diagnosis index of the volumetric efficiency of the hydraulic pump, when the hydraulic pump does not have its own displacement indication sensor, the volumetric efficiency of the hydraulic pump will be difficult to diagnose. The pressure value can realize real-time fault diagnosis of the volumetric efficiency of the hydraulic pump and improve the comprehensiveness of the hydraulic system fault early warning.

Hydraulic motors can be divided into fixed hydraulic motors and variable hydraulic motors. When the hydraulic motor is a fixed-displacement motor, the volumetric efficiency of the fixed-displacement hydraulic motor can be fault diagnosed in the following ways, as detailed below.

The first method: the volumetric efficiency of the hydraulic motor = (theoretical flow rate of the hydraulic motor/the input flow rate of the hydraulic motor) × 100%.

Among them, the theoretical flow rate of the hydraulic motor = the theoretical displacement of the hydraulic motor × the rotation speed of the hydraulic motor.

The input main oil pipeline of the hydraulic motor can be determined by the rotation direction of the hydraulic motor, and data information corresponding to the first flow sensor or the second flow sensor in the input main oil pipeline is obtained, which is the input flow rate of the hydraulic motor.

The second method: the volumetric efficiency of the hydraulic motor = (output flow of the hydraulic motor/input flow of the hydraulic motor) × 100%

Among them, the input main oil pipeline and the output main oil pipeline in and out of the hydraulic motor can be determined according to the rotation direction of the hydraulic motor, and the input flow of the hydraulic motor can be obtained through the flow sensors of the input main oil pipeline and the output main oil pipeline in the main pipeline. and the input flow of the hydraulic motor.

In this embodiment, when the volumetric efficiency of the hydraulic motor is less than the sixth preset threshold, it may be determined that the hydraulic motor is faulty. A fault warning threshold can also be set. The fault warning threshold is greater than the sixth preset threshold. When the volumetric efficiency of the hydraulic pump is less than the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is that the volumetric efficiency of the hydraulic motor is low. When the hydraulic pump When the volumetric efficiency of the motor is greater than or equal to the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is that the volumetric efficiency of the hydraulic motor is normal. Among them, the fault warning threshold and the sixth preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the fault warning threshold may be 80%, and the sixth preset threshold may be 70%.

When the hydraulic motor is a variable hydraulic volume motor, the volumetric efficiency of the variable hydraulic motor can be fault diagnosed in the following ways, as detailed below.

The first method: the volumetric efficiency of the hydraulic motor = (output flow of the hydraulic motor/input flow of the hydraulic motor) × 100%.

Among them, the main oil pipeline in and out of the hydraulic motor can be determined according to the rotation direction of the hydraulic motor, and the flow in and out of the hydraulic motor can be read through the first flow sensor or the second flow sensor of the main pipeline.

Second method: If the hydraulic motor does not have a flushing valve, the volumetric efficiency of the hydraulic motor can be calculated based on the fourth flow sensor to obtain the housing drain flow of the hydraulic motor and the output flow of the hydraulic motor, then:

The volumetric efficiency of the hydraulic motor = the output flow of the hydraulic motor/(the output flow of the hydraulic motor + the housing drain flow of the hydraulic motor).

In this embodiment, when the volumetric efficiency of the hydraulic motor is less than the sixth preset threshold, it may be determined that the hydraulic motor is faulty. A fault warning threshold can also be set. The fault warning threshold is greater than the sixth preset threshold. When the volumetric efficiency of the hydraulic pump is less than the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is that the volumetric efficiency of the hydraulic motor is low. When the hydraulic pump When the volumetric efficiency of the motor is greater than or equal to the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is that the volumetric efficiency of the hydraulic motor is normal. Among them, the fault warning threshold and the sixth preset threshold can be set according to actual needs, and are not specifically limited in this embodiment. For example, the fault warning threshold may be 80%, and the fifth preset threshold may be 70%.

When the hydraulic motor is a variable motor and the hydraulic motor does not have a displacement indication sensor, the volumetric efficiency of the hydraulic motor can also be faulted in the following ways, as detailed below.

Referring to FIG. 7 , FIG. 7 is a schematic flowchart of a fault diagnosis method for volumetric efficiency of a hydraulic motor provided by an embodiment of the present disclosure. The fault diagnosis method provided in this embodiment includes the following steps:

S601: According to the preset data collection rules, obtain the third actual flow rate of the hydraulic motor corresponding to the fault diagnosis indicator in the hydraulic system, the third rotation speed of the hydraulic motor, and the fifth and sixth pressure values at both ends of the servo piston in the hydraulic motor. , the fault diagnosis index is the volumetric efficiency of the hydraulic motor.

In this embodiment, the calculation formula of the volumetric efficiency is: (theoretical flow rate of the hydraulic motor/input flow rate of the hydraulic motor)*100%, where the theoretical flow rate of the hydraulic motor=theoretical displacement of the hydraulic motor×the rotation speed of the hydraulic motor, the hydraulic pressure The third actual flow rate of the motor is the input flow rate of the hydraulic motor. The input flow rate of the hydraulic motor can be obtained by collecting the first flow sensor or the second flow sensor on the main oil pipeline. Wherein, it can be determined according to the rotation direction of the hydraulic motor in the hydraulic system whether the data information collected by the first flow sensor or the second flow sensor is used as the input flow rate of the hydraulic motor.

Among them, the fifth pressure value and the sixth pressure value at both ends of the servo piston in the hydraulic motor are collected by the seventh pressure sensor and the eighth pressure sensor. The third rotation speed of the hydraulic motor can be obtained by the second rotation speed sensor. Of course, it is also The third rotation speed of the hydraulic pump can be obtained indirectly by referring to the above.

S602: Determine the third theoretical flow rate of the hydraulic motor based on the fifth pressure value, the sixth pressure value and the third rotation speed.

In this embodiment, the third theoretical flow rate of the hydraulic motor can be determined in the following manner:

Determine the third theoretical displacement of the hydraulic pump based on the fifth pressure value, the sixth pressure value, the ninth pressure value, the second maximum displacement and the tenth pressure value;

According to the third theoretical displacement and the second rotation speed, the third theoretical flow rate is determined.

Among them, the third theoretical displacement = (P ₅ -P ₆ -P ₀₃ )×V ₂ /(P ₀₄ -P ₀₃ )

In the above formula, P ₅ represents the fifth pressure value, P ₆ represents the second pressure value, P ₀₃ represents the ninth pressure value, V ₁ represents the first maximum displacement, P ₀₄ represents the tenth pressure value, P ₅ >P ₆ , the positive and negative of the fifth pressure value and the sixth pressure value can indicate the direction of the output flow of the hydraulic motor, so when P ₅ <P ₆ , the third theoretical displacement = (P ₆ -P ₅ -P ₀₃ )× V ₂ /(P ₀₄ -P ₀₃ ).

In the above, the difference between the fifth pressure value and the sixth pressure value can represent the displacement of the hydraulic motor. The change of the pressure value is proportional to the change of the displacement. Therefore, the fifth pressure value and the sixth pressure can be used to calculate the displacement of the hydraulic motor. The pressure difference is used as a measure of displacement. Furthermore, there will be a dead zone (0＜P＜P ₀₃ ) during the starting process of the second swash plate in the hydraulic motor, that is, the displacement will not be output as soon as there is a difference between the fifth pressure value and the sixth pressure value. Therefore, it is necessary to find out and remove the influence of the dead zone on the displacement calculation during debugging; similarly, when the hydraulic pump displacement is limited, when the pressure difference exceeds the upper limit of the displacement, the displacement does not change with the fifth pressure value and the sixth pressure value. As the pressure difference between the pressure values increases and continues to increase, the displacement is the second maximum displacement (V ₁ ) of the set hydraulic motor. Among them, the ninth pressure value corresponding to the second swash plate dead zone in the hydraulic motor and the second maximum displacement of the hydraulic motor are both determined through pre-debugging and can be directly called and used when performing fault diagnosis.

S603: Determine the third volumetric efficiency of the hydraulic motor based on the third actual flow rate and the third theoretical flow rate.

Among them, the third volumetric efficiency of the hydraulic motor can be determined through the third actual flow rate and the third theoretical flow rate according to the above-mentioned calculation formula of the hydraulic pump volumetric efficiency.

S604: Determine whether the preset diagnosis condition corresponding to the fault diagnosis index is met. The preset diagnosis condition is that the third volumetric efficiency is less than the sixth preset threshold.

In this embodiment, a fault warning threshold can also be set. The fault warning threshold is greater than the sixth preset threshold. When the third volumetric efficiency of the hydraulic motor is less than the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis index is the hydraulic pump. The volumetric efficiency is low. When the third volumetric efficiency of the hydraulic motor is greater than or equal to the fault warning threshold, the fault diagnosis result corresponding to the fault diagnosis indicator is that the volumetric efficiency of the hydraulic motor is normal. The settings of the sixth preset threshold and the fault warning threshold may refer to the above description, and will not be described again in this embodiment.

S605: When the preset diagnosis conditions corresponding to the fault diagnosis index are met, the fault diagnosis result corresponding to the fault diagnosis index is a hydraulic motor failure.

S606: When the preset diagnosis conditions corresponding to the fault diagnosis index are not met, the fault diagnosis result corresponding to the fault diagnosis index is that the hydraulic motor is normal.

S607: According to the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

In this embodiment, when the fault diagnosis result is that the hydraulic motor is faulty, a fault warning can be provided through the display screen or other methods mentioned above; when the fault diagnosis result is that the hydraulic motor is normal, a reminder can also be provided through the display screen or other methods mentioned above.

It can be seen that when performing fault diagnosis on the fault diagnosis index of the volumetric efficiency of the hydraulic motor, when there is no corresponding sensor, the volumetric efficiency of the hydraulic motor will be difficult to diagnose. By using the pressure value at both ends of the servo piston, the hydraulic pressure can be realized. Real-time fault diagnosis of the motor's volumetric efficiency improves the comprehensiveness of hydraulic system fault warning.

Referring to FIG. 8 , FIG. 8 is a schematic flowchart of a fault diagnosis method for oil replenishment of an oil charge pump provided by an embodiment of the present disclosure. The fault diagnosis method provided in this embodiment includes the following steps:

S701: According to the preset data collection rules, obtain the oil charge pressure value of the oil charge pump corresponding to the fault diagnosis index in the hydraulic system, the first fault diagnosis result corresponding to the volumetric efficiency of the hydraulic pump, and the second fault corresponding to the volumetric efficiency of the hydraulic motor. Diagnosis results and fault diagnosis indicators are the oil replenishment status of the oil charge pump.

In this embodiment, the charge pressure value of the charge pump can be collected by the ninth pressure sensor, and the first fault diagnosis result corresponding to the volumetric efficiency of the hydraulic pump and the second fault diagnosis result corresponding to the volumetric efficiency of the hydraulic motor can be obtained. The method may refer to the above description, and will not be described again in this embodiment.

S702: Determine whether the preset diagnosis conditions corresponding to the fault diagnosis indicators are met. The preset diagnosis conditions are that the first fault diagnosis result is that the hydraulic pump is normal, the second fault diagnosis result is that the hydraulic motor is normal and the oil supply pressure value is less than the seventh preset threshold. .

In this embodiment, when the oil charge pressure value is less than the seventh preset threshold, it may be related to the volumetric efficiency of the hydraulic pump and the volumetric efficiency of the hydraulic motor. When it is determined based on the volumetric efficiency of the hydraulic pump that the hydraulic pump fails or the hydraulic motor fails. When the volumetric efficiency determines that the hydraulic motor is faulty, the charge pump may not be faulty. It can only be determined when the charge pressure value is less than the seventh preset threshold, the first fault diagnosis result is that the hydraulic pump is normal, and the second fault diagnosis result is that the hydraulic motor is normal. The charge pump is faulty. In this embodiment, the seventh preset threshold can be set according to actual needs, and is not specifically limited in this embodiment.

S703: When the preset diagnosis conditions corresponding to the fault diagnosis index are met, the fault diagnosis result corresponding to the fault diagnosis index is a charge pump failure.

S704: When the preset diagnosis conditions corresponding to the fault diagnosis index are not met, the fault diagnosis result corresponding to the fault diagnosis index is that the charge pump is normal.

In this embodiment, failure to meet the preset diagnosis condition corresponding to the fault diagnosis index specifically refers to that the oil supply pressure value is greater than or equal to the seventh preset threshold.

S705: Based on the fault diagnosis results, perform fault warning operations corresponding to the fault diagnosis indicators.

In this embodiment, when the fault diagnosis result is that the oil charge pump is faulty, a fault warning can be provided through the display screen or other methods mentioned above; when the fault diagnosis result is that the oil charge pump is normal, a reminder can also be provided through the display screen or other methods mentioned above.

It can be seen that when performing fault diagnosis on the fault diagnosis index of the oil replenishment condition of the oil charge pump, the fault diagnosis results of the pressure sensor in the oil charge pump, the volumetric efficiency of the hydraulic pump and the fault diagnosis results of the volumetric efficiency of the hydraulic motor are integrated to carry out the fault diagnosis. Fault diagnosis improves the accuracy of fault diagnosis.

To sum up, the fault early warning method provided by the embodiments of the present disclosure, during the fault early warning process of the hydraulic system, takes into account the connection between the data information collected by different sensors, and targets a fault diagnosis index by obtaining the fault diagnosis index. The data information of multiple parameters related to the indicator is processed, so that the fault diagnosis results of the fault diagnosis indicator are more accurate, and the fault diagnosis indicators that cannot be directly obtained through the sensor can be processed. Carrying out fault early warning improves the comprehensiveness of hydraulic system fault early warning.

It should be noted that in this article, relational terms such as “first” and “second” are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is no such actual relationship or sequence between entities or operations. Furthermore, the terms "comprises," "comprises" or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, circuit, article, or device including a list of elements includes not only those elements, but also those not expressly listed or other elements inherent to such process, circuit, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, circuit, article, or device including the stated element.

The above-mentioned specific embodiments further describe the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above-mentioned are only specific embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Protection scope: Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this disclosure shall be included in the protection scope of this disclosure.

Claims

Fault warning methods for hydraulic systems include:

According to the preset data collection rules, obtain the target data information of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system;

Determine the fault diagnosis result corresponding to the fault diagnosis indicator according to the obtained target data information;

According to the fault diagnosis result, a fault warning operation corresponding to the fault diagnosis indicator is performed.
The method according to claim 1, wherein the fault diagnosis indicator is clogging of the oil suction filter;

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the pressure difference value of the oil suction filter and the first temperature value of the hydraulic oil tank;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

When the pressure difference value is greater than the first preset threshold and the first temperature value is greater than or equal to the second preset threshold, the oil suction filter is clogged. The second preset threshold represents the oil in the hydraulic oil tank. low temperature preset value.
The method according to claim 1 or 2, wherein the fault diagnosis indicator is the oil suction condition of the hydraulic pump;

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the negative pressure value of the oil suction pipeline and the second temperature value of the hydraulic oil tank;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

When the negative pressure value is less than or equal to the third preset threshold, the oil suction resistance of the hydraulic pump is large and the oil suction valve in the hydraulic pump is not opened;

When the negative pressure value is greater than the third preset threshold, the negative pressure value is less than the fourth preset threshold, and the second temperature value is less than the second preset threshold, the oil suction resistance of the hydraulic pump is large. And the oil temperature in the hydraulic oil tank is low, the second preset threshold represents the low temperature preset value of the oil in the hydraulic oil tank, and the fourth preset threshold is greater than the third preset threshold;

When the negative pressure value is greater than the third preset threshold, the negative pressure value is less than the fourth preset threshold, and the second temperature value is greater than or equal to the second preset threshold, then the hydraulic pressure The pump has high suction resistance and the suction filter is clogged.
The method according to any one of claims 1 to 3, the fault diagnosis index is the volumetric efficiency of a hydraulic pump, and the hydraulic pump is a variable hydraulic pump:

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the first actual flow rate of the hydraulic pump, the first rotation speed of the hydraulic pump, and the first pressure value and the second pressure value at both ends of the servo cylinder in the hydraulic pump;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

Determine the first theoretical flow rate of the hydraulic pump according to the first pressure value, the second pressure value and the first rotation speed;

determining a first volumetric efficiency of the hydraulic pump based on the first actual flow rate and the first theoretical flow rate;

When the first volumetric efficiency is less than the fifth preset threshold, the hydraulic pump fails.
The method of claim 4, when the fault diagnosis index is the volumetric efficiency of the hydraulic pump and the hydraulic pump is a variable hydraulic pump, the acquisition of at least two target parameters corresponding to the fault diagnosis index in the hydraulic system target data information, including:

Obtain the second actual flow rate of the hydraulic pump, the second rotation speed of the hydraulic pump, and the third pressure value and the fourth pressure value at both ends of the reversing valve in the hydraulic pump;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

Determine the second theoretical flow rate of the hydraulic pump according to the third pressure value, the fourth pressure value and the second rotation speed;

determining a second volumetric efficiency of the hydraulic pump based on the second actual flow rate and the second theoretical flow rate;

When the second volumetric efficiency is less than the fifth preset threshold, the hydraulic pump fails.
The method according to claim 5, the fault diagnosis index is the volumetric efficiency of a hydraulic motor, and the hydraulic motor is a variable hydraulic motor:

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the third actual flow rate of the hydraulic motor, the third rotation speed of the hydraulic motor, and the fifth and sixth pressure values at both ends of the servo piston in the hydraulic motor;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

Determine a third theoretical flow rate of the hydraulic motor according to the fifth pressure value, the sixth pressure value and the third rotation speed;

determining a third volumetric efficiency of the hydraulic motor according to the third actual flow rate and the third theoretical flow rate;

When the third volumetric efficiency is less than the sixth preset threshold, the hydraulic motor fails.
The method according to claim 6, the first theoretical flow rate and the second theoretical flow rate are determined in the following manner;

Determine the seventh pressure value corresponding to the dead zone of the first swash plate in the hydraulic pump, the first maximum displacement of the hydraulic pump, and the eighth pressure value corresponding to the first maximum displacement;

Determine the first theoretical displacement of the hydraulic pump according to the first pressure value, the second pressure value, the seventh pressure value, the first maximum displacement and the eighth pressure value;

Determine a second theoretical displacement of the hydraulic pump according to the third pressure value, the fourth pressure value, the seventh pressure value, the first maximum displacement and the eighth pressure value;

The first theoretical flow rate is determined based on the first theoretical displacement and the first rotation speed, and the second theoretical flow rate is determined based on the second theoretical displacement and the first rotation speed.
The method according to claim 6 or 7, the third theoretical flow rate is determined in the following manner:

Determine the ninth pressure value corresponding to the dead zone of the second swash plate in the hydraulic motor, the second maximum displacement of the hydraulic motor, and the tenth pressure value corresponding to the second maximum displacement;

Determine a third theoretical displacement of the hydraulic pump according to the fifth pressure value, the sixth pressure value, the ninth pressure value, the second maximum displacement and the tenth pressure value;

The third theoretical flow rate is determined based on the third theoretical displacement and the third rotation speed.
The method according to any one of claims 6 to 8, wherein the fault diagnosis indicator is the oil replenishment condition of the oil charge pump;

The obtaining target data information of at least two target parameters corresponding to fault diagnosis indicators in the hydraulic system includes:

Obtain the charge pressure value of the charge pump, the first fault diagnosis result corresponding to the volumetric efficiency of the hydraulic pump, and the second fault diagnosis result corresponding to the volumetric efficiency of the hydraulic motor;

Determining the fault diagnosis results corresponding to the fault diagnosis indicators includes:

When the first fault diagnosis result is that the hydraulic pump is normal, the second fault diagnosis result is that the hydraulic motor is normal, and the oil charge pressure value is less than a seventh preset threshold, then the oil charge pump is faulty.
The method according to any one of claims 1 to 9, further comprising:

After the hydraulic system is started, when the working time of the hydraulic system reaches the preset time threshold, the target data of at least two target parameters corresponding to the fault diagnosis indicators in the hydraulic system are obtained according to the preset data collection rules. Information steps.